Regulation of Immunoreactive Activin A Secretion from Cultured Rat Anterior Pituitary Cells

• Published in: ENDOCRINE JOURNAL 1996, Vol.43(1), pp.39-44
• Main Authors: LIU, ZHONG-HUI, SHINTANI, YASUMI, WAKATSUKI, MAKI, SAKAMOTO, YUKIHIRO, HARADA, KAZUYO, ZHANG, CHEN-YU, SAITO, SHIRO
• Format: Article
• Language: English
• Subjects: Activin; Activins; Animals; Anterior pituitary cells; Cells, Cultured; Female; Follicle Stimulating Hormone - pharmacology; Follicle-stimulating hormone; Gonadotropin-Releasing Hormone - pharmacology; Humans; Immunohistochemistry; Inhibins - metabolism; Kinetics; Luteinizing Hormone - pharmacology; Luteinizing hormone-releasing hormone; Pituitary Gland, Anterior - metabolism; Protein kinase C; Protein Kinase C - metabolism; Radioimmunoassay; Rats; Rats, Wistar; Tetradecanoylphorbol Acetate - pharmacology
• ISSN: 0918-8959; 1348-4540
• DOI: 10.1507/endocrj.43.39

Immunoreactive activin A (ir-activin A) release from cultured rat anterior pituitary cells was examined by measuring iractivin A in culture medium by a specific radioimmunoassay. Ir-activin A release into the medium increased over 1-18 days, and reached a maximal level at 12-15 days. The basal levels of ir-activin A in the culture media were 0.70±0.10 (mean±SD), 1.30±0.36 and 1.83±0.44ng/106 cells, when cultured for 6 days with 0, 2 and 10% fetal calf serum, respectively. LHRH induced an approximate 1.4-fold increase in ir-activin A release in contrast to a 40-60% inhibition with FSH, but LH did not affect the activin A release. In the presence of 12-o-tetradecanoylphorbol acetate (TPA), ir-activin A release was enhanced, but no significant effect was induced by forskolin. Activin A was distinctly immunostained in cultured rat anterior pituitary cells. These results suggested that activin A release from the pituitary is modified by FSH and LHRH, and that the activation of protein kinase C may be involved in the action of LHRH.